The Corona Warning App of the German Federal Government – How perceived data protection issues hindered any effectiveness

Müller-Török, Robert and Prosser, Alexander (2021) The Corona Warning App of the German Federal Government – How perceived data protection issues hindered any effectiveness. Smart Cities and Regional Development (SCRD) Journal, 5 (2). pp. 23-31. ISSN 2537-3803

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Since June 17th, 2020 the Corona Warn App of the German Federal Government has been available for download. After a sharp increase downloads stagnate around a total of 20 million, which is roughly one fourth of the population. Whether everyone who downloaded it actually uses it, is questionable. ObjectivesWe want to show that the underlying concept of an app is questionable, even if each inhabitant with a smartphone downloads and uses it, it would cover barely half of each encounter where COVID-19 could actually be transmitted. Prior workThis work is the scientific, extended version of a short article we published in the September 2020 issue of the “Behördenspiegel”, a monthly magazine covering German public administration issues. ApproachWe use statistical methods to show that, (i) even in the very best case with a perfectly working app the coverage would have been roughly half of all relevant encounters (ii) and that the voluntary usage of this app as well as the free decision of the infected individual to publish its (anonymized) data to warn others in fact reduces any effectiveness considerably. In addition we show that (iii) due to the design of the app there is a likely limit where the app will not be able to warn its users for mathematical and cryptographical reasons. ResultsWe demonstrate by statistical means that this app could never have worked and why similar apps neither would work, let aside probably the “Trace Together” initiative of Singapore, which is based on a combination of an app plus physical tokens for those who do not own nor use smartphones ( We define some requirements a successful COVID-19 tracing solution must fulfill. ImplicationsWe show that such apps arenot a solution for the problem, rather an obstacle to a real solution, because they lull their (few) users into a false sense of security which is obviously wrong, based on real figures. Value The paper contributes to transparency of government action during the COVID-19 pandemic. We show that other ways of contact tracing must be pursued in order to be effective and hinder the pandemic from escalating rather than providing a false feeling of safety.

Item Type: Article
Keywords: Bluetooth, contract tracing, COVID-19, smartphone
Divisions: Departments > Wirtschaftsinformatik u. Operations Mgmt > Produktionsmanagement > Taudes
Version of the Document: Published
Depositing User: Gertraud Novotny
Date Deposited: 12 Jul 2021 15:27
Last Modified: 12 Jul 2021 15:27
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